The Saturday Night Live alum told Howard Stern on Wednesday that he preferred Justin Timberlake to Justin Bieber.

Hader appeared on Stern's Sirius XM radio show and complimented the older Justin for his professionalism.

"He's great," Hader said. "Also, the guy doesn't show up with anybody. It's just him."

Hader did not extend the same fondness for the 19-year old. The funnyman said that the Baby singer arrived with an entourage of about 20 guys when he appeared on SNL earlier this year. He felt that Bieber could learn from Timberlake on how to conduct himself.

"He (Bieber) had a guy holding a slice of pizza. A guy holding a Diet Coke. You're trying to fight through all these people to get dressed. Timberlake, it was just him. He's a real class act, that guy," Hader said.

Hader is just the latest celebrity to take aim at Bieber's actions. Rock legend Jon Bon Jovi blasted the young crooner as an "a--hole" who was disrespectful to his fans. Jovi made his comments to The London Standard while on tour in Vienna on May 20. The frontman of Jon Bon Jovi was critical of how Bieber has treated fans in the past few months.

Bieber has canceled shows and showed up two hours late for his show at the O2 arena in London in March.

"They run the risk of disrespecting their audience members who have worked hard to pay for their ticket, to give you the permission to take two or three hours of their lives - or in that kid's case, 80 minutes of their lives," the rocker said.

The comments from Jovi came Bieber being booed at the Billboard Awards on Sunday. He won the first ever Milestone Award and was greeted to the stage by a chorus of boos. Bieber appeared taken aback before telling the audience that he was an "artist" and deserved to be taken seriously.

"It should be about the craft that I'm making, and... this is not a gimmick, this is not a gimmick. I'm an artist, and I should be taken seriously. All this other bull should not be spoken of," HE said.

Bieber may have referenced his recent backlash with a series on tweets on Tuesday. The Canadian wrote that he knew who he was and that he was giving back.

Bieber surprised fans at Whitney Elementary School in Las Vegas on May 17. He gave out food and vowed to fill the pantry for the next year.